ITRM930069A1 - PROCEDURE FOR PRODUCING INSULATED COATS IN ENCAPSULATED FIBERGLASS - Google Patents

Description

PROCEDURE FOR PRODUCING ENCAPSULATED FIBROUS INSULATING CLOTHES

Field of the Invention.

The present invention relates to a fibrous insulation material. Pi? particularly it relates to a process for producing an encapsulated glass fiber insulation covering.

Background of the Invention

Fibrous insulation products are available in various densities. for use in a variety? of different applications. Such a product? a low weight fiberglass mantle used on insulated structures that require a high degree of insulation, for example aircraft hulls. In such an environment,? important that the weight is minimal, so? not to unnecessarily increase the weight of the aircraft, and that the mantle is capable of providing an effective barrier to the high noise levels and cold temperatures encountered during flight.

Typical products used for this purpose consist of fine glass fibers bonded together in the form of a blanket and having a density of about 0.3 pounds per cubic foot to 1.5 pounds per cubic foot. Depending on the size of the space to be insulated, a single mantle or several stacked mantles are wrapped and secured in a film, for example by seaming or heat sealing, and the wrapped insulation is then attached to the aircraft fuselage by means of of pins connected to the hull of the airplane. Although such products satisfactorily perform their insulating function, their relatively low tensile strength offers poor resistance to the stresses encountered during manufacture and installation. The handling of the individual layers and the manufacture of the product in multiple layers subject the material to additional stresses which tend to damage the weak glass fiber material.

In addition, since? the commercial product usually requires an external film to allow the insulating mantle to be handled and installed as desired, the effectiveness of the insulation will be. reduced during service if water vapor condensation is trapped in the film insulation.

It has been suggested to replace the conventional insulation product previously discussed with a low weight glass fiber insulation mantle having an air permeable backing sheet adhering to one of the major faces of the mantle, with the other major face and with the elongated edges of the mantle encapsulated in a non-porous film or other material, for example the porous support material itself. The support improves the tensile strength of the insulation product and increases its stiffness. Furthermore, its permeability? allows the free passage of air entering and exiting the mantle. This, in turn, allows the evaporation of any humidity. from the insulation put in place, such as that which would be encountered in an airplane installation, when the insulation is installed with the cladding material facing the passenger side of the airplane.

Such a product could of course be manufactured by the insulation installer through the separate purchase of the glass fiber blanket, permeable backing sheet and non-porous film and applying the backing and cladding materials to the blanket. However, it would be much preferable for the installer to purchase a fully formed ready-to-use product directly from the glass fiber manufacturer. This, in turn, requires the glass fiber manufacturer to be able to rapidly and economically mass produce such an encapsulated product, without the need for it. of large capital investments. Furthermore, such a manufacturing process must be capable of being carried out at the same speed. to which the glass fiber mantle is manufactured, so as not to require slowing down the speed? of production of the same glass fiber mantle.

Brief summary of the Invention In compliance? with the invention, a mantle consisting of glass fibers bonded together by a binder is formed and a support sheet is bonded to the longest face of the mantle. The blanket is continuously advanced through a coating application station, the lower face of the blanket being the face to which the carrier sheet is bonded. A web of liner material is continuously applied to the major top face of the liner at the liner application station, the width of the web being greater than the width of the liner to an extent that the web extends over the side edges of the aldyl? of the lower major face. The portions of the tape that. they extend beyond the lower major face are continuously brought into contact with the support sheet so as to overlap the support sheet adjacent to the side edges of the mantle and the overlapping portions of the web are made to adhere to the mantle. Preferably, the overlapping portions of the film and the carrier sheet are adhered by welding or heat sealing the film to the carrier sheet. For example, pulse thermal welding could be performed.

The permeable backing sheet can be made to adhere to the mantle in any of several ways. The preferred method exploits the apparatus for forming the glass fiber mantle which uses a mobile permeable collecting surface, for example a ribbon or a chain, on which a mixture of glass fibers and unbound binder is collected. In accordance with With the invention, a web of the air permeable backing sheet material is provided on the collecting surface, allowing suction applied below the collecting surface to facilitate collection of the fibers on the backing sheet web. Following the hardening of the binder, the fibers are tied together and the web of the support material is tied to the face of the mantle.

Alternatively, a web of backing sheet material is continuously applied to the major upper face of the mantle, preferably before the mantle passes through the curing oven, and the mat is then turned over to allow it to pass through the station. application of the coating.

The invention allows the encapsulation of very low weight glass fiber blankets without damaging the integrity. of the mantle. Can you? appreciate that the encapsulation of such fragile material requires sensitive handling, while still being capable of applying sufficient force to satisfactorily make the web materials adhere to the mantle.

These and other characteristics and the various aspects of the invention, as well as the relative benefits, will be made more evident. clear in the following detailed description of the preferred embodiments.

Brief description of the drawings Figure 1? a schematic representation of a preferred method used to produce a glass fiber insulation blanket with a backing sheet adhering to a major face thereof;

Figure 2 is a partial schematic plan view of a cracking operation carried out on the mantle as it emerges from the binder hardening oven;

Figure 3 is a partial illustrative view of the coating operation according to the invention;

Figure 4 is an enlarged cross-sectional view, taken on line 4-4 of Figure 3;

Figure 5 is an enlarged cross-sectional view taken along line 5-5 of Figure 3;

Figure 6 is an enlarged cross-sectional view taken along line 6-6 of Figure 3;

Figure 7 is an enlarged cross-sectional view taken along line 7-7 of Figure 3;

Figure 8? a partial schematic representation of a modified portion of the apparatus of FIG. 1 showing the introduction of an overlay tape over the insulating product;

Figure 9 is a partial illustrated view of the apparatus for overturning or inverting a curtain prior to the coating operation;

Figure 10? a partial schematic representation of a carrier tape applying means located downstream from the curing oven; And

Figure 11 is a cross-sectional view of a modified insulation product consisting of a plurality of materials. of stacked plies encapsulated in the backing and liner sheets, each ply being similar to the ply shown in Figure 5.

Detailed description of the preferred embodiments

With reference to Figure 1, which illustrates the preferred manufacturing process of the supported blanket according to the invention, a source 10 feeds glass fibers 12 which are sprayed with the binder by means of the nozzles 14 as the fibers move. towards a mobile screen 16. The source can? be of any desired type, for example a rotary spinning machine, into which the molten glass is introduced and which, upon rapid rotation, causes the molten glass to exit under centrifugal force through small holes in the side walls, resulting in the formation of fibers. A cos? said flame-thinning process or "pot and marble" process could also be used, in which the pebbles or glass fragments are melted in a vase and the molten glass is extracted from the vase through sun bus in the form of fibers.

Which one of these procedures or a pr? different failure is used as the source of the fibers, a blanket of glass bifres is normally produced by directing a stream of air-entrained fibers against the movable screen 16. The movable screen, which? known in the art as a collector chain,? typically constituted by a continuous metal conveyor with open weave, dragged around the rollers 18, 20 and 22. A suction is created within the path of the collecting chain by any convenient means, for example by means of suction boxes 24 mounted directly below the collecting chain in the. current upward and in the downward flow between roll 20 and rollers 18 and 22. The vacuum or negative pressure in the collector chamber in which the collector chain runs causes the air stream carrying the fibers to pass through towards the collecting chain. Since? the openings provided in the chain are sufficiently small to filter out most of the fibers that come into contact with them, the fibers so? filtered are deposited on the chain and are able to support the fibers which are then deposited on them. By doing this, a layer of glass fibers of predetermined weight or thickness is produced. Will you understand? that the speed? of production of the fibers, the type of the produced fibers and the speed? of the collecting chain are all correlated to provide control over the weight and thickness of the layer.

The manufacturing process typically comprises a continuous conveyor 26 which is drawn around a roller 28 located in proximity to the material. of the collector chain 16. The fibrous layer is transferred from the collector chain to the conveyor 26 and may also be contacted on its upper surface with an upper conveyor 30 arranged such that the space between the conveyors 30 and 26 immediately prior to the entry into the kiln 32 corresponds to the desired final thickness of the mantle. The layer can? also be compressed by conveyors or rollers inside the furnace, in a manner not shown, to achieve the desired final thickness. The heat in the oven hardens the binder on the fibers and the hardened binder holds the fibers in place.

In accordance with with the preferred method of applying the permeable support material to one face of the mantle, a nastrop of air permeable material 34 is extracted from a roller 36 by means of the rollers 38 and 40 and is directed towards the stream upwards of the collector chain 16. The pressure difference existing on opposite sides of the collector chain causes the web 34 to contact and be supported by the collector chain. Since? the material of the tape? highly permeable, the current of air that carries the fibers? able to pass through? towards the ribbon, placing the fibers directly on the ribbon. The tape thus effectively functions as the outer surface of the collecting chain, moving simultaneously with it.

As shown in Figure 1, the fibers have accumulated on the outer surface of the web 34 to form an L layer while the web? supported by the collector chain 16. When the fibrous layer is separated from the collector chain in transfer to the conveyor 26, the web of permeable material is separated together with it, whereby the fibrous layer L and the web 34 are fed as a whole to the furnace 32. In it, the hardening of the binder results not only in the fibers being bound together, but also in the fibers being bound to the web 34. The finished blanket B? shown in the position of exit from the oven 32.

Typically, the collector chain and the furnace are more? wide of the desired width of the mantle. If there? occurs in practice, the mantle will come? cut into strips of the desired width, for example by means of the strip cutter 42 in Figure 2. Any convenient means, for example the angled conveyors 44 and 46, can be employed to direct the resulting coats B'and B " on diverging paths. It will be understood that the apparatus depicted in Figure 2 is for illustrative purposes only and that more than one strip cutter may be provided, in case of necessity.

With reference to Figure 3, the mantle is transported from the oven to a coating station F arranged downstream. Even though the entire blanket B or one of the smaller blankets resulting from the strip cutting operation could be fed to the coating station, depending on the desired width of the finished product, for convenience it will be assumed. that the mantle has been cut into strips and that the portion passing through the coating station is constituted by the mantle B1. As shown in Figure 4, the final product when approaching the coating station takes the mantle B1, the bottom face of which? adhered to the support material 34.

The coating station can? consist of any convenient arrangement for applying a coating material to the mantle. As illustrated, it comprises a roll 48 of coating material 50 which overlaps the movable element. The coating material is withdrawn from the roll in the form of a web which passes beneath the guide roller 51 adjacent the upper surface of the curtain. The length of the roll and the width of the web of the covering material are greater than the width of the covering, so that the web of covering material overlaps the upper surface of the covering. There? ? shown in Figure 5, which shows the tape 50 draped over the lateral edges of the mantle B1 and extending below the lower surface of the mantle.

Downstream of the coating station are the stationary folding skids 52, positioned in the path of the draped marginal portions of the coating tape. How ? well known in the folding field, the skids are tapered so that each draped marginal portion of the web is progressively folded as the blanket and web pass through the skids, until the edges of the web are completely folded. , as shown in Figure 6. Immediately downstream of the folding skids are one or more? rollers 54, 56 which press the folded edges in the web firmly upward against the bottom surface of the carrier sheet 34. The edges of the web are then adhered to the underside of the carrier sheet, preferably by heat sealing of the impulsive type. As illustrated in Figures 3 and 7, the coils 58 connected to the downstream rollers 56 indicate that the rollers 56 are heated to soften the web material to the point where it adheres to the carrier sheet 34. Obviously, if desired, Other means may be employed to heat the web material.

Note that the conveyor 44 which moves the mantle through the apparatus? pi? narrow to the width of the coat. There? ? shown in Figures 4-7, in which the edges of the conveyor 44 are spaced from the edge of the curtain sufficiently to provide space for the folding shoes 52 and for the pressure and heat rollers 54, 56 and why? the edge portions of the web are folded up against the undersurface of the backing sheet 34.

If the method of applying a carrier sheet to the underside of a layer of glass fibers as described with reference to FIG. 1 is not employed, the carrier sheet may be used. be applied instead to the upper surface of the layer of glass fibers in the manner illustrated in Figure 8. The layer of glass fibers in this case is collected directly on the collecting chain 16 and a web of material. of support 34 is applied to the upper surface of the layer L by the roller 36 upstream of the furnace 32 and the upper press conveyor 30. As in the process of Figure 1, the hardening of the binder in the layer makes it possible. tie the fibers together and do? so that the support material 34 is bonded to the upper surface of the resulting mantle.

When the carrier sheet is applied to the top surface of the glass fiber layer,? it is necessary to invert the mantle downstream of the kiln in order to present the mantle to the cladding station with the support side down. Can you? employing any convenient means of reversing or overturning. For the sake of illustration, the mantle 8 'in Figure 9? invert? by means of the angled roller 60 positioned downstream from the conveyor 62, after which the curtain is moved towards the coating station F by the conveyor 44 located at a lower level in comparison with the conveyor 62.

If desired, the Carrier Sheet can be applied at a point downstream rather than upstream from the kiln. There? ? shown in Figure 10, where the web of sheet material 34 is pulled from the roll 36 in the same manner as in Figure 8, however, in addition, it receives a spray of adhesive from the nozzle 64 in order to adhere the web. to the mantle. In such an arrangement, the resulting naturally coated sheet should be inverted, as previously discussed.

As shown in Figure 7, the product resulting from the process described? a slightly compressed mantle B, consisting of bonded fibers, a support sheet 34 of permeable material bonded to a major face of the mantle and of? a non-porous film wrapped around the opposite major face and the two lateral edges of the covering and bonded to the marginal portions of the support sheet. There? leaves to encapsulate only the transverse edges created when the mantle is cut to the length requested by the customer.

Although the backing material must be sufficiently permeable not to impede the flow of air through the collector chain during the manufacturing process or through the liner sheet of the installed clad insulation blanket, it should be capable of increasing the load of tensile failure of the final product and should have sufficient mechanical strength to remain intact during. the process of harvesting the fibers. A sheet capable of functioning in the manner described should be porous, strong, tear resistant and light in weight, for example less than 1.5 ounces per square yard. In general, it can? be any porous or woven or non-woven reinforcement or canvas consisting of organic or inorganic fibers, with a flame retardant system that meets flammability requirements. of the regulatory code expressed in the United States by 49 CFR part 25 (FAR 25.853) or BMS 8-142 and by the toxicity requirements? of the fumes expressed in the United States by the FAR 25.853 and ATS 10007001 standards. the air of the backing sheet should be such that the air can pass through one square foot of the material in quantity. within the range of 500 to 1,000 cubic feet per minute, the measurement being made in accordance with with the permeability test? to air, by Frazer (ASTM D 737-1982). In addition, the carrier sheet material should be heat sealable to the film used to encapsulate the top face and longitudinal edges of the ply. An example of such a material? the polyester cloth available from the Snow Filtration Company and marketed under the name Reemay.

The material of the film can? comprise any of the conventional non-porous films currently employed in the installation of insulation blankets in aircraft. An example ? a film made by Orcon, available from Or with Corporation. The film used must be capable of being sealed or heat sealed.

The invention is not? limited to a single layer of mantle, as discussed so far, but can? includes re a plurality? of stacked layers of mantles. As shown in Figure 11, two layers of the overlapping supported membranes B1 and B "are encapsulated by the film 50 in the same manner described above, with the ends of the film adhering to the support sheet adjacent the edges of the mantle. of such a product is performed in the same manner as it is performed in the single layer product manufacturing process, except that another ply is laid over the first ply before reaching the coating station. this operation can be carried out with any convenient means, for example by having the mantles B "shown in Figures 2 to 9 lay down on the top? of the mantle B 'or by introducing another mantle. Obviously, this last choice would be made if the mantle exiting the kiln were of full width.

Will you recognize? that the invention provides an inexpensive process for producing an improved insulation product which does not require excessive modifications or additions to the basic glass fiber production line and does not slow down speed. for the production of glass fibers.

It should now be apparent that the invention need not necessarily be limited to all the specific details described with reference to the preferred embodiments, but that modifications to the specific features of the preferred embodiments and which do not alter the overall basic function and the concept of the invention can be made without with what? departing from the spirit and scope of the invention defined in the attached claims.

Claims (13)

CLAIMS 1. A process for the production of a glass fiber insulation covering having a support sheet on one of its major faces and a covering sheet on the opposite major interface and on the side edges, comprising the following operations: forming a mantle consisting of glass fibers bonded together by a binder; making a support sheet adhere to a major face of the mantle; continuously moving the mantle with the backing sheet facing down through a liner application station; Continuously apply a web of liner material to the major top face of the liner at the liner application station, the width of the belt exceeding the width of the liner to such an extent that the web extends over the side edges of the liner beyond the lower major face; continuously folding the portions of the web extending beyond the major lower face in contact with the backing sheet so as to overlap it adjacent to the side edges of the mantle; And adhere the overlapping portions of the ribbon to the backing sheet. 2. A method according to claim 1, wherein the carrier sheet? permeable to air 3. Process according to claim 2, wherein the coating material? a non-porous film and the overlapping portions of the film and the carrier sheet are adhered by welding or heat sealing between the film and the carrier sheet. The method according to claim 3, wherein the overlapping portions of the web are folded upwards against the carrier sheet by stationary folding skids. 5. The method of claim 3 wherein heated rolls are used to press the overlapping portions of the film against the carrier sheet and to heat seal the latter to the film. 6. Process according to claim 2, wherein the mantle? formed by collecting a mixture of glass fibers and uncured binder on an air permeable movable support surface covered with a web of backing sheet material, applying suction through the permeable support surface and the web of supporting sheet material. support to facilitate the collection of the glass fibers and making the binder harden, the hardened binder performing the function of binding the fibers together and making the tape of support material adhere to the mantle. 7. A method according to claim 1, wherein a web of backing sheet material is continuously applied to the major upper face of the curtain, the method including the operation of inverting or inverting the curtain prior to its passage through the station. application of the coating. 8. A method according to claim 7, wherein the web of backing sheet material is applied prior to curing of the binder, the subsequent hardening of the binder involving adhesion of the backing sheet material to the mantle. 9. A method according to claim 2, wherein the carrier sheet? a porous cloth woven or non-woven. 10. A process according to claim 9, wherein the ply? made of polyester. 11. Process according to claim 1, wherein the covering has a density? between 0.2 pounds per cubic foot and 1.5 pounds per cubic foot and the thickness of the coat? in the range of 3/8 inch to 2 inch. 12. A method according to claim 1, wherein the surface to which the web of coating material is adhered? the lower mantle in a plurality? of stacked mantles. 13. Process according to claim 1, comprising the step of cutting the movable curtain into strips continuously so as to obtain ribbons of smaller width and separating the resulting smaller layers. tight before applying the coating material.